Impulse repeater



Nov. 24, 1936. w. KROLL El AL 2,061,802

IMPULSE REPEATER Filed May 23, 49:55 2 Sheets-Sheet 1 N 9 f a y INVENTOR. WALTER K R0 L L GEORGE ZAPF ATTORNEY.

Nov. 24, 1936. w. KROLL ET AL 2,061,302

I IMPULSE REPEATER I Filed May 23, 1935 2 Sheets-Sheet 2 INVENTOR. WALTER KROLL GEORGE ZAPF ATTORNEY.

Patented Nov. 24, 1936 FATE IMPULSE REPEATER Walter Kroll and Georg Zapf, Berlin, Germany,

assignors to Siemens & Halske Aktiengesellschaft, Siemensstadt. near Berlin, Germany Application May 23, 1935, Serial No. 23,112 In Germany May 24, 1934 14 Claims. (Cl. 179-16) The present invention concerns a circuit arrangement for rep-eating impulses in long distance communication systems, particularly telephone systems, having devices for the correction of the impulses. Insuch systems difficulties arise in that on the one hand, long impulses occur on account of distortion, for example during selection, which should be shortened to the proper length, and on the other hand, long impulses occur which are produced intentionally, for example for release in the case of alternating current selection, which should be passed on unshortened.

- To satisfy both conditions at the same time is diflicult and only possible by detailed switching and then the disadvantage frequently arises that not only the selecting impulses but also the releasing impulses are passed on corrected so that on releasean undesirable switching process is brought about, such as the connection of ringing current to the desired subscriber. The present invention obviates this disadvantage in that the impulse repeater relay only causes the repeating ofeach received impulse on the termination of the latter, and is so influenced through auxiliary relays that the length of the repeated impulses is always brought to the necessary value for producing proper operation.

The attached Figures 1 and 2 illustrate embodi- 'ments of the invention, while Fig. 3 is a diagram. Only those switching .means necessary for understanding the invention are shown.

In Fig. 1, LI represents the incoming end of a junction line with leads a and b, while L2 rep-' resents the outgoing end of this line. The incoming impulses are received by the alternating current receivingrelay J I. The relay J I is alternatelyenergized and deenergized by the impulses. On the energizing of relay J I, the following circuit for relay MI is closed: earth, contact 47'I, winding of relay MI, battery, earth. Relay MI closes the following circuit for relay VI earth, contact I Iml, windings I and II of relay VI, battery, earth. Relay VI energizes and short circuits its winding I through its contact IBuI. thus acts as a slowacting relay and holds during an impulse train. Relay VI by the opening of its two contacts 212i and 3'uI disconnectsduring the transmission 'of the impulses, the incoming line from the outgoing line. At the end of the impulse, relay J I releases and consequently relay MI releases. Since relay VI holds during the impulse train, the following circuit is formed for relay GI on the release of relay MI: earth,

contacts IZmI, IS'IJI, I5tI, winding of relay GI, battery, earth. Relay GI maintains relay VI energized over contact IIlg-I after the release of re lay MI. Relay GI locks itself in. the following circuit, independently of relay TI: earth, contacts I'IgI, Ithl, winding of relay GI, battery, earth. Relay GI also closes the following circuit for the relay TI: earth, contacts IlgI, IiigI, winding of relay TI, battery, earth. As long as relay MI is de-energized relay TI holds independently of relay GI in the following circuit: earth, contacts IZmI, I3ol, Mil, winding of relay-Tl, battery, earth. After relays-GI and TI have energized earth is applied to the outgoing a-lead over the contacts 28 and Zilgl shown in dotted lines and the impulse is thus repeated. After relays GI and. TI have energized the following circuit is completed for relay HI: earth, contacts 8tI, 9yl, winding I of relay HI, battery, earth. Relay HI energizes and takes over the repetition of the impulse over the a-lead by. applying earth bymeansof contact IhI. The holding circuit for relay GI is broken after relay HI energizes, by the opening of contact Iiihl. Relay GI releases. The repeating of the impulse on the a-lead would, however, be brought to an end on account of the opening of contact Zlyl if the further repeating of the impulse had not been taken over by the relay HI, as already mentioned. After the release of relay GI, relay HI also deenergizes, on account of the opening of contact SlgI. Relay HI makes a delayed release, because the winding II of relay Hi is short-circuited through contact Sml and hence the relay acts as a slow acting relay. On the next impulse relay JI again energizes. Relay JI effects the energizingof relay MI. Relay MI by opening its contact I Zml effects the release of relay TI and again closes, through a contact I ImI, the circuit for the slow acting relay VI. After the termination of this impulse relays J I and MI again release. The interaction between relays GI, TI and HI already described, again sets in and effects the repeating of the impulse.

The manner of working of the correcting device is made more easily understood by reference to Fig. 3 in which various incoming impulses, some of them extremely distorted, are shown diagrammatically. The scale of the diagram is chosen so that 1 mm. on the abscissa represents 2 milliseconds.

The diagram I shows the case in which the make period of the incoming impulse occupies 60 milliseconds (ms) and the break period 40 ms.

The relay J I is therefore energized for 60 ms. and deenergized for 40 ms. Since relay MI may take 10 ms. in which to operate, this energizes after 10 ms. Relay VI (which remains operated during the Whole impulse train) may take the same time to operate, 10 ms. after the release of relay MI relay GI energizes similarly, relay TI energizes 10 ms. after relay GI, and after a further 10 ms. relay HI energizes. Relay GI releases 10 ms. after the energizing of relay HI. Relay TI releases 10 ms. after the energizing of relay MI or relay GI. The corrected impulse extended through relay HI is illustrated on the abscissa HI by continuous lines. It can be seen from this figure that the relay HI whose winding I is deenergized after the release of relay GI, is energized considerably more than 10 ms. after this, and in this case it follows that after the relays J I and MI have again been energized, through the second incoming impulse at the beginning of the first energizing of relay HI, the winding II of relay HI, previously short circuited over contact 5mI, is short circuited over the circuit: earth, contact IiI, GmI, winding II of relay HI, contact 'IhI, earth, and is thereby made slow to release. The time for release thus produced occupies 80 ms. Since the repeating of the impulse begins after the energizing of relays GI and TI, over contacts 20H and 2IgI, the total duration of the repeated impulse is 50 ms. of which 10 ms. is effected by relays GI and TI (shown by dotted lines on the HI axis) and 40 ms. by relay HI.

Diagram 2 illustrates a number of impulses in which the current make lasts for 50 ms. and the current break lasts for 30 ms. As is apparent from the diagram the method of operation of the arrangement according to the invention does not differ in this case from that of diagram I. The total duration of the repeated impulse again occupies 50 ms.

Diagram 3 is drawn up on the assumption that the impulse make lasts for 20 ms. and the impulse break lasts 40 ms. It follows from this diagram that the short circuit for relay HI, after its first energization through the contacts '47 I and Sml already closed by the second impulse, is again interrupted after the energizing of relay HI on account of the opening of contact MI. Relay MI holds in the following circuit, in this case: earth, contact 'IhI, winding II of relay HI, contact ImI, winding of relay MI, battery, earth. In this circuit the winding II of relay HI, which forms a diiferential winding with respect to winding I of this relay, is energized. This effects the immediate undelayed release of relay HI. The impulse repeated through the contact IhI correspondingly lasts 30 ms. To this there is still to be added 10 ms. through the closing of contacts 2IgI and 20H, as shown in dotted lines on the HI axis. Relay MI released 10 ms. after the release of relay HI. As is indicated in the diagram, the duration of the second impulse extended over contact IhI, only amounts to 20 ms. It is, however, increased by 10 ms. by relays GI and TI to a total of 30 ms.

Diagram 4 shows quite an arbitrary distortion of each of the incoming impulses of an impulse train unlikely to occur in practice. Thus the first current make lasts for 40 ms., the first current break for 20 ms., the second current make 50 ms., the second current break 30 ms., the third current make 30 ms., the third current break l ms., the fourth current make 20 ms., the fourth current break 50 ms., and the fifth current make 60 ms. As can be seen immediately from the diagram of the repeated impulses are elastically adapted to the incoming impulses. The duration of a repeated impulse never falls below 30 ms.

It should be mentioned that the connection to earth over the connection and contacts 20 and 'ZIQI indicated by dotted lines, can be dispensed with if the pause, which is determined by the time of release of relay MI plus the sum of the time taken to energize by relays GI, TI and HI, is not too long. This is the case, for example, when the release times do not as assumed in the diagram amount to 10 ms., but for example only actually amount to 5 ms. In this case relay HI by itself always extends impulses of sufficient length.

This is the case assumed in Figure 2 which shows essentially the same arrangement as Fig. 1. In addition Figure 2 exhibits a special feature in that the precaution is taken that besides the correction applied to each [individual impulse the first impulse of each impulse train experiences an additional lengthening. This happens for the following reason: since in the case of. traffic over several junction lines with impulse correcting devices in each individual stage, particularly if the correcting devices only correct in an arbitrary manner and are not self-adjusting, on account of the difference in loss between the first and second impulse of each impulse train, the second impulse approaches nearer to the first one from stage to stage and thereby an absorption of impulses occurs after a few stages, it is necessary to provide correcting devices in individual intermediate stages which prolong the first impulse and thereby, of course, cause a greater pause between impulses I and 2, so that even over a great number of connecting stages it is possible to obtain a passage of. impulses which is free from objection.

In Fig. 2 the impulse receiving relay J2 is alternately energized and deenergized through the mcoming impulses from the line LI. Relay J2 by closing its contact 672 energizes the relay M2.

By closing its contact IIm2 relay M2 energizes the slow acting relay V2. Relay V2 holds during each impulse, and by the opening of. its contact IvZ, disconnects the outgoing line L2 from the incoming line LI during each impulse train. In addition relay V2, by closing its contact I802, prepares a circuit for relay G2, and by closing its contact '02, it prepares a circuit for the winding II of relay K2. At the end of the first closing of the circuit relays J2 and M2 release. Through the release of relay M2 the relay G2 is energized in the following circuit: earth, contacts I 'Im2, I802, 2It2, winding of. relay G2, battery, earth. Relay G2 energizes and by closing its contact 5g2 connects earth to the a-lead. The repeating of the first impulse over the a-lead is thereby initiated. After the operation of relay G2 and the release of relay M2, relay V2 holds over the contact I592. energized by relay G2 in the following circuit: earth, contact 2392, winding of relay T2, battery, earth. After relay T2 has energized the following circuit is closed for relays K2 and H2: earth, contacts I 2g2, I3t2, winding I of relay K2, winding I of relay H2, battery, earth. Relays H2 and K2 operate in this circuit. Relay K holds independently of relays G2 and T2 in the following circuit:

earth, contacts I0k2, I Iv2, winding II of relay K2,

battery, earth. Relay K2 by opening its contact 47:12, removes the earth connected to the a-lead, on the operation of relay G2, over contact 5g2.

Furthermore relay T2 is,

' corresponds to that of Figure 1.

The repeating of the: impulses is, however, taken up at the 'same instant on account of earth being connected to the a-lead .through contact '3h2. After the "operation of relay H2 the relay G2 releases on account-of the opening of contact l9h2. After the release of G2 the circuit for the winding I of relay H2 is broken. If a second impulse has not yet arrived over the line Ll the relay H2 releases slowly on account ofthe short circuit of the differential winding II, through contact 8m2. An illustration of the method" of operation of the correcting deviceinthe case of *variouskinds of impulse distortions according to Figure 2, by means of. diagrams is omitted for it completely It therefore need only be mentioned that the prolonging of the first'impulse by the connection of earth to the a-lead immediately relay G2 energizes, cannot be repeated in the case of the other impulses of an'impulse train, since after energizing relay K2 holds, during the duration of an impulse train, over WindingII. On the termination ofthe impulse train the holding circuit for winding II-of relay K2 is broken on account of the release of relay'V'2. Relay K2 releases and prepares, by

closing its contact M2, the immediate repeating of the first impulse of the next impulse train, on the energizing of relay G2, and hence the prolonging of this impulse.

Having described the invention, what is considered to be new and is desired to be protected by Letters Patent will be set forth in the following claims.

What is claimed is:

1. In an impulse correcting repeater arranged to respond to the impulses of a series by transmitting a corrected series of impulses responsive to the receipt of the incoming series of impulses, means for causing the repeating of each impulse of a series only upon the termination of each incoming impulse of a series, and means for causing the repeated impulses to be always of a certain length.

2. In an impulse correcting repeater arranged to receive a series of incoming impulses and to transmit a corrected outgoing impulse for each incoming impulse of a series, and means efiective only responsive to the reception of the complete incoming impulse for transmitting an outgoing impulse of a minimum length.

3. In an impulse correcting repeater arranged to receive a series of. incoming impulses and. responsive thereto to transmit a corrected outgoing series of impulses, an impulse repeating relay, means for operating said repeating relay to repeat an impulse only responsive to the termination of an incoming impulse, and means for governing the length of the repeated impulse.

4. In an impulse correcting repeater arranged to receive a series of incoming impulses and to repeat a corrected series of outgoing impulses, a repeating relay, said repeating relay operated to repeat an outgoing impulse only responsive to the termination of an incoming impulse, and means including said repeating relay for elastically adapting the length of the repeated impulses relative to the incoming impulses.

5. In an impulse correcting repeater arranged to receive a series of incoming impulses and to repeat a corrected series of outgoing impulses, an impulse receiving relay, a repeating relay having its energizing circuit controlled by said impulse receiving relay, means for opening the circuit of said repeating relay independent of said impulse receiving relay, and means controlled by said impulse receiving relay and depending upon the duration-of the received impulses for controlling the time interval taken by said repeating relay to release: and terminate the outgoing impulse.

6. In an impulse correcting repeater arranged to receive a series of incoming impulses and transmit acorrected series of outgoing impulses, a repeating relay, an impulse receiving relay, auxiliary relays operated responsive to the deenergization of said impulse receiving relay to eifect energization of said repeating relay, and means controlled by said impulse receiving relay and depending upon the length of an incoming impulse for governing the time interval occupied by said repeating relay to release and terminate the length of the outgoing impulse.

7. Inan impulse correcting repeater arranged to receive series of impulses and transmit corrected series of impulses, an impulse receiving relay, a repeating relay, said impulse receiving relay when operated closing the operating circuit of said repeating relay, means for opening the operating circuit of said repeating relay to terminate the outgoing impulse independent of said receiving relay, and means for controlling the release time of said repeating relay depending upon the condition of energization of said receiving relay.

8. In an impulse correcting repeater arranged to receive series of impulses and transmit corrected series of impulses, an impulse receiving relay, a repeating relay, said impulse receiving relay when operated closing the operating circuit of said repeating relay, means for opening the operating circuit of said repeating relay to terminate the outgoing impulse independent of said receiving relay, and means for controlling said repeating relay so it operates with a delayed release or a rapid release according to the condition of energization of said impulse receiving relay.

9. In an impulse correcting repeater arranged to receive series of impulses and transmit corrected series of impulses, an impulse receiving relay, a repeating relay having two windings, said impulse receiving relay when operated closing the circuit of one of said windings of said repeating relay to operate the same, means for opening the circuit of said repeating'relay winding to terminate the outging impulse independent of said receiving relay, and means dependent upon the operating condition of said receiving relay for delaying the release of said repeating relay, said delayed release means comprising a short circuit of the second winding of said repeating relay by said receiving relay.

10. In an impulse correcting repeater arranged to receive series of impulses and transmit corrected series of impulses, an impulse receiving relay, an auxiliary relay operated by said receiving relay, a repeating relay having two 11. In an impulse correcting repeater arranged to receive series of impulses and transmit corrected series of impulses, an impulse receiving relay, an auxiliary relay operated by said receiving relay, a repeating relay having two windings operated over'one winding by joint control of said receiving and said auxiliary relays, means controlled independent of said receiving and auxiliary relays for releasing said repeating relay, and means controlled by said receiving relay for short circuiting the second winding of said repeating relay to delay its release, said short circuit being removed by the release of said impulse receiving relay and said second winding then being connected in circuit with said auxiliary relay.

12. In an impulse correcting repeater arranged to receive a series of impulses and to transmit a corrected series of outgoing impulses, an impulse receiving relay, an auxiliary relay operated by said receiving relay, a repeating relay having two windings and operated by joint control of said receiving and auxiliary relays over one of said windings, means for releasing said repeating relay independent of said receiving and auxiliary relays, means controlled by said receiving relay for short circuiting said second winding of said repeating relay to delay its release in case the auxiliary relay is released, said second winding arranged differentially with respect to the first winding, and means for energizing said second winding in series with said auxiliary winding in case said auxiliary relay is operated to efiect the rapid release of said repeating relay.

'13. In an impulse correcting repeater arranged to receive a series of impulses and to transmit a corrected series of outgoing impulses, means for effecting the repeating of a corrected outgoing impulse of a series responsive to the termination of an incoming impulse of a. series, and means for prolonging the first one of an outgoing series of impulses.

14. In an impulse correcting repeater arranged to receive a series of impulses and to transmit a corrected series of outgoing impulses, a pair of repeating relays, both of said relays operated responsive to the receipt of the first one of an incoming series of impulses, means for deenergizing one of said relays during the receipt of the remaining impulses of the series, and means controlled by the energized one of said relays for prolonging the length of the first impulse of the outgoing corrected series of impulses.

' WALTER KROLL.

GEORG ZAPF. 

